1. Field of the Invention
The present invention relates to a technique for cutting an electrical wiring line disposed beforehand on a substrate, and more particularly, to a technique which cuts, for isolation, electrical wiring lines one from another which have been shorted to each other to avoid static breakdown, in the manufacturing process of an electronic device such as a display device of liquid-crystal or organic electro-luminescence (EL), or a semiconductor device.
2. Description of the Related Art
Electronic devices, such as a liquid-crystal display device and a semiconductor device, are subject to a breakdown due to static in the manufacturing process thereof. To avoid a breakdown due to static electricity, predetermined electrical wiring lines on a substrate on which a driver IC is to be mounted are shorted by a shorting line until the driver IC is mounted on the substrate. Immediately prior to the mounting of the driver IC, the shorting line is cut using a laser or the like so that the electrical wiring lines are isolated from each other (Se the first embodiment and FIG. 1 in Japanese Unexamined Patent Application Publication 1-230020, for example).
Since the cutting of each of the electrical wiring lines or the shorting line is carried out at one location only, the isolation of the lines from each other is not fully assured because of dirt sticking to the lines or wiring defects. To avoid such isolation failure between the lines, a cutting operation may be repeated. However, repeated cutting operations lead to prolonged process time. When a substrate bearing a plurality of liquid-crystal panels is diced to a product size, the electrical wiring lines are also cut for isolation at the same time. Such a dual-purpose operation becomes impossible, depending on the shape and the structure of the liquid-crystal panel.